[RFC,10/13] drm/msm/disp/dpu1: Add support for DSC in encoder

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 8d942052db8a..18cb1274a8bb 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -21,12 +21,17 @@ 
 #include "dpu_hw_intf.h"
 #include "dpu_hw_ctl.h"
 #include "dpu_hw_dspp.h"
+#include "dpu_hw_dsc.h"
 #include "dpu_formats.h"
 #include "dpu_encoder_phys.h"
 #include "dpu_crtc.h"
 #include "dpu_trace.h"
 #include "dpu_core_irq.h"
 
+#define DSC_MODE_SPLIT_PANEL		BIT(0)
+#define DSC_MODE_MULTIPLEX		BIT(1)
+#define DSC_MODE_VIDEO			BIT(2)
+
 #define DPU_DEBUG_ENC(e, fmt, ...) DPU_DEBUG("enc%d " fmt,\
 		(e) ? (e)->base.base.id : -1, ##__VA_ARGS__)
 
@@ -135,6 +140,7 @@  enum dpu_enc_rc_states {
  * @cur_slave:		As above but for the slave encoder.
  * @hw_pp:		Handle to the pingpong blocks used for the display. No.
  *			pingpong blocks can be different than num_phys_encs.
+ * @hw_dsc		Handle to the DSC blocks used for the display.
  * @intfs_swapped:	Whether or not the phys_enc interfaces have been swapped
  *			for partial update right-only cases, such as pingpong
  *			split where virtual pingpong does not generate IRQs
@@ -180,6 +186,7 @@  struct dpu_encoder_virt {
 	struct dpu_encoder_phys *cur_master;
 	struct dpu_encoder_phys *cur_slave;
 	struct dpu_hw_pingpong *hw_pp[MAX_CHANNELS_PER_ENC];
+	struct dpu_hw_dsc *hw_dsc[MAX_CHANNELS_PER_ENC];
 
 	bool intfs_swapped;
 
@@ -566,6 +573,8 @@  static struct msm_display_topology dpu_encoder_get_topology(
 			struct drm_display_mode *mode)
 {
 	struct msm_display_topology topology = {0};
+	struct drm_encoder *drm_enc;
+	struct msm_drm_private *priv;
 	int i, intf_count = 0;
 
 	for (i = 0; i < MAX_PHYS_ENCODERS_PER_VIRTUAL; i++)
@@ -1008,7 +1017,8 @@  static void dpu_encoder_virt_mode_set(struct drm_encoder *drm_enc,
 	struct dpu_hw_blk *hw_ctl[MAX_CHANNELS_PER_ENC];
 	struct dpu_hw_blk *hw_lm[MAX_CHANNELS_PER_ENC];
 	struct dpu_hw_blk *hw_dspp[MAX_CHANNELS_PER_ENC] = { NULL };
-	int num_lm, num_ctl, num_pp;
+	struct dpu_hw_blk *hw_dsc[MAX_CHANNELS_PER_ENC];
+	int num_lm, num_ctl, num_pp, num_dsc;
 	int i, j;
 
 	if (!drm_enc) {
@@ -1061,11 +1071,16 @@  static void dpu_encoder_virt_mode_set(struct drm_encoder *drm_enc,
 	dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
 		drm_enc->base.id, DPU_HW_BLK_DSPP, hw_dspp,
 		ARRAY_SIZE(hw_dspp));
+	num_dsc = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
+		drm_enc->base.id, DPU_HW_BLK_DSC, hw_dsc, ARRAY_SIZE(hw_dsc));
 
 	for (i = 0; i < MAX_CHANNELS_PER_ENC; i++)
 		dpu_enc->hw_pp[i] = i < num_pp ? to_dpu_hw_pingpong(hw_pp[i])
 						: NULL;
 
+	for (i = 0; i < MAX_CHANNELS_PER_ENC; i++)
+		dpu_enc->hw_dsc[i] = i < num_dsc ? to_dpu_hw_dsc(hw_dsc[i]) : NULL;
+
 	cstate = to_dpu_crtc_state(drm_crtc->state);
 
 	for (i = 0; i < num_lm; i++) {
@@ -1810,10 +1825,179 @@  static void dpu_encoder_vsync_event_work_handler(struct kthread_work *work)
 			nsecs_to_jiffies(ktime_to_ns(wakeup_time)));
 }
 
+static int dpu_encoder_dsc_update_pic_dim(struct msm_display_dsc_config *dsc,
+					  int pic_width, int pic_height)
+{
+	if (!dsc || !pic_width || !pic_height) {
+		DPU_ERROR("invalid input: pic_width=%d pic_height=%d\n",
+			  pic_width, pic_height);
+		return -EINVAL;
+	}
+
+	if ((pic_width % dsc->drm.slice_width) || (pic_height % dsc->drm.slice_height)) {
+		DPU_ERROR("pic_dim=%dx%d has to be multiple of slice=%dx%d\n",
+			  pic_width, pic_height, dsc->drm.slice_width, dsc->drm.slice_height);
+		return -EINVAL;
+	}
+
+	dsc->drm.pic_width = pic_width;
+	dsc->drm.pic_height = pic_height;
+
+	return 0;
+}
+
+static void
+dpu_encoder_dsc_pclk_param_calc(struct msm_display_dsc_config *dsc, u32 width)
+{
+	int slice_per_pkt, slice_per_intf;
+	int bytes_in_slice, total_bytes_per_intf;
+
+	if (!dsc || !dsc->drm.slice_width || !dsc->slice_per_pkt) {
+		DPU_ERROR("Invalid DSC/slices\n");
+		return;
+	}
+
+	slice_per_pkt = dsc->slice_per_pkt;
+	slice_per_intf = DIV_ROUND_UP(width, dsc->drm.slice_width);
+
+	/*
+	 * If slice_per_pkt is greater than slice_per_intf then default to 1.
+	 * This can happen during partial update.
+	 */
+	if (slice_per_pkt > slice_per_intf)
+		slice_per_pkt = 1;
+
+	bytes_in_slice = DIV_ROUND_UP(dsc->drm.slice_width *
+				      dsc->drm.bits_per_pixel, 8);
+	total_bytes_per_intf = bytes_in_slice * slice_per_intf;
+
+	dsc->eol_byte_num = total_bytes_per_intf % 3;
+	dsc->pclk_per_line =  DIV_ROUND_UP(total_bytes_per_intf, 3);
+	dsc->bytes_in_slice = bytes_in_slice;
+	dsc->bytes_per_pkt = bytes_in_slice * slice_per_pkt;
+	dsc->pkt_per_line = slice_per_intf / slice_per_pkt;
+}
+
+static void
+dpu_encoder_dsc_initial_line_calc(struct msm_display_dsc_config *dsc,
+				  u32 enc_ip_width)
+{
+	int ssm_delay, total_pixels, soft_slice_per_enc;
+
+	soft_slice_per_enc = enc_ip_width / dsc->drm.slice_width;
+
+	/*
+	 * minimum number of initial line pixels is a sum of:
+	 * 1. sub-stream multiplexer delay (83 groups for 8bpc,
+	 *    91 for 10 bpc) * 3
+	 * 2. for two soft slice cases, add extra sub-stream multiplexer * 3
+	 * 3. the initial xmit delay
+	 * 4. total pipeline delay through the "lock step" of encoder (47)
+	 * 5. 6 additional pixels as the output of the rate buffer is
+	 *    48 bits wide
+	 */
+	ssm_delay = ((dsc->drm.bits_per_component < 10) ? 84 : 92);
+	total_pixels = ssm_delay * 3 + dsc->drm.initial_xmit_delay + 47;
+	if (soft_slice_per_enc > 1)
+		total_pixels += (ssm_delay * 3);
+	dsc->initial_lines = DIV_ROUND_UP(total_pixels, dsc->drm.slice_width);
+}
+
+static bool
+dpu_encoder_dsc_ich_reset_override_needed(struct msm_display_dsc_config *dsc, bool pu_en)
+{
+	/* As per the DSC spec, ICH_RESET can be either end of the slice line
+	 * or at the end of the slice. HW internally generates ich_reset at
+	 * end of the slice line if DSC_MERGE is used or encoder has two
+	 * soft slices. However, if encoder has only 1 soft slice and DSC_MERGE
+	 * is not used then it will generate ich_reset at the end of slice.
+	 *
+	 * Now as per the spec, during one PPS session, position where
+	 * ich_reset is generated should not change. Now if full-screen frame
+	 * has more than 1 soft slice then HW will automatically generate
+	 * ich_reset at the end of slice_line. But for the same panel, if
+	 * partial frame is enabled and only 1 encoder is used with 1 slice,
+	 * then HW will generate ich_reset at end of the slice. This is a
+	 * mismatch. Prevent this by overriding HW's decision.
+	 */
+	return pu_en && dsc && (dsc->drm.slice_count > 1) &&
+		(dsc->drm.slice_width == dsc->drm.pic_width);
+}
+
+static void dpu_encoder_dsc_pipe_cfg(struct dpu_hw_dsc *hw_dsc,
+				     struct dpu_hw_pingpong *hw_pp,
+				     struct msm_display_dsc_config *dsc,
+				     u32 common_mode, bool ich_reset)
+{
+	if (hw_dsc->ops.dsc_config)
+		hw_dsc->ops.dsc_config(hw_dsc, dsc, common_mode, ich_reset);
+
+	if (hw_dsc->ops.dsc_config_thresh)
+		hw_dsc->ops.dsc_config_thresh(hw_dsc, dsc);
+
+	if (hw_pp->ops.setup_dsc)
+		hw_pp->ops.setup_dsc(hw_pp);
+
+	if (hw_pp->ops.enable_dsc)
+		hw_pp->ops.enable_dsc(hw_pp);
+}
+
+static void dpu_encoder_prep_dsc(struct dpu_encoder_virt *dpu_enc,
+				 struct msm_display_dsc_config *dsc)
+{
+	/* coding only for 2LM, 2enc, 1 dsc config */
+	struct dpu_encoder_phys *enc_master = dpu_enc->cur_master;
+	struct dpu_hw_dsc *hw_dsc[MAX_CHANNELS_PER_ENC];
+	struct dpu_hw_pingpong *hw_pp[MAX_CHANNELS_PER_ENC];
+	int this_frame_slices;
+	int intf_ip_w, enc_ip_w;
+	int ich_res, dsc_common_mode;
+	int pic_width, pic_height;
+	int i;
+
+	for (i = 0; i < MAX_CHANNELS_PER_ENC; i++) {
+		hw_pp[i] = dpu_enc->hw_pp[i];
+		hw_dsc[i] = dpu_enc->hw_dsc[i];
+
+		if (!hw_pp[i] || !hw_dsc[i]) {
+			DPU_ERROR_ENC(dpu_enc, "invalid params for DSC\n");
+			return;
+		}
+	}
+
+	dsc_common_mode = 0;
+	pic_width = dsc->drm.pic_width;
+	pic_height = dsc->drm.pic_height;
+
+	dpu_encoder_dsc_update_pic_dim(dsc, pic_width, pic_height);
+
+	dsc_common_mode = DSC_MODE_MULTIPLEX | DSC_MODE_SPLIT_PANEL;
+	if (enc_master->intf_mode == INTF_MODE_VIDEO)
+		dsc_common_mode |= DSC_MODE_VIDEO;
+
+	this_frame_slices = pic_width / dsc->drm.slice_width;
+	intf_ip_w = this_frame_slices * dsc->drm.slice_width;
+
+	dpu_encoder_dsc_pclk_param_calc(dsc, intf_ip_w);
+
+	/*
+	 * dsc merge case: when using 2 encoders for the same stream,
+	 * no. of slices need to be same on both the encoders.
+	 */
+	enc_ip_w = intf_ip_w / 2;
+	dpu_encoder_dsc_initial_line_calc(dsc, enc_ip_w);
+
+	ich_res = dpu_encoder_dsc_ich_reset_override_needed(dsc, false);
+
+	for (i = 0; i < MAX_CHANNELS_PER_ENC; i++)
+		dpu_encoder_dsc_pipe_cfg(hw_dsc[i], hw_pp[i], dsc, dsc_common_mode, ich_res);
+}
+
 void dpu_encoder_prepare_for_kickoff(struct drm_encoder *drm_enc)
 {
 	struct dpu_encoder_virt *dpu_enc;
 	struct dpu_encoder_phys *phys;
+	struct msm_drm_private *priv;
 	bool needs_hw_reset = false;
 	unsigned int i;
 
@@ -1841,6 +2025,10 @@  void dpu_encoder_prepare_for_kickoff(struct drm_encoder *drm_enc)
 			dpu_encoder_helper_hw_reset(dpu_enc->phys_encs[i]);
 		}
 	}
+
+	priv = drm_enc->dev->dev_private;
+	if (priv->dsc)
+		dpu_encoder_prep_dsc(dpu_enc, priv->dsc);
 }
 
 void dpu_encoder_kickoff(struct drm_encoder *drm_enc)